Presently, a majority of dental disease occurs on interproximal surface areas of teeth (i.e. the surface areas between teeth). A program of good dental hygiene which includes keeping the interproximal surface areas clean helps prevent dental disease from occurring in these areas.
Flossing is a well known and commonly used method of good dental hygiene by which interproximal surfaces of teeth are cleaned. Proper flossing cleans the interproximal surfaces both above and below the gum line thereby reducing the likelihood of dental disease on these surfaces. Although flossing is a valuable part of good dental hygiene, it is a tedious and time consuming task and, therefore, is seldom done properly. Cleaning the interproximal areas of teeth has been a problem since the existence of teeth.
There are various methods of cleaning teeth. Each method has limitations with regard to cleaning the interproximal surfaces of teeth. Toothbrushes are used to clean teeth. However, toothbrushes cannot adequately clean interproximal surface areas because of the lack of access to these areas. Toothpicks are also used to clean teeth and also suffer from an inability to reach all interproximal surfaces adequately. Hydraulic dental irrigation systems may be used to clean these areas. However, it is well accepted that hydraulic irrigation alone is inadequate to remove the sticky plaque films which build up on teeth surfaces including interproximal surfaces.
The best method of cleaning the interproximal surfaces of teeth is to have a dental cleaning done by a health professional. However, dental flossing is generally regarded as the next best and the most convenient way a lay person can properly clean between his or her own teeth.
If done properly, dental flossing is a highly effective method of improving dental hygiene and health of both teeth and periodontium (gum tissues and underlying jaw bone) which is between natural teeth and/or dental restorations in the mouth. Flossing action actually mechanically cleans bacteria laden plaque from tooth surfaces, particularly from interproximal tooth surfaces. Essentially, the floss wipes or scrubs off plaque and other undesirable debris from tooth surfaces. Although flossing is commonly known to be as important and as necessary as tooth brushing, it is widely neglected. Some of the most common complaints about flossing (and, therefore, reasons for neglect) include that it is difficult to perform and is time consuming.
A variety of devices have been introduced which attempt to make flossing easier. Most of these devices simply act as holders for the floss to reduce the manual dexterity required to floss. While such floss-holder devices may simplify some aspects of flossing, they generally have a fixed or limited range of motion and, therefore, have limited cleaning action and effectiveness. In addition, floss-holder devices are used manually, the cleaning energy conveyed to plaque covered tooth surfaces must be supplied by the user.
Electrically powered devices for flossing and cleaning teeth have also been introduced. Most of these devices directly connect floss or floss-holding assemblies to a power source such as an electric motor. Because of the direct connection between the motor and the flossing element, whether it is by drive shafts, gears, pulleys, cams, or etc., these devices impart gross movement of the floss between the teeth which is forceful, jerky, and/or "sawing" or "hatchet-like" in nature. These types of movement can be both inefficient and potentially harmful.
Generally, these electrically powered devices comprise flossing assemblies attached to well known electric toothbrush handles. Thus, many electric flossers utilize the up and down or back and forth movement of an electric toothbrush assembly. Many devices have been described which reciprocate a strand of floss back and forth between teeth thereby resulting in a sawing motion. See, e.g., Brien, U.S. Pat. No. 3,847,167; Lecouturier, U.S. Pat. No. 4,245,658; Salyer, U.S. Pat. No. 4,265,257; Hinding, U.S. Pat. No. 4,326,549; Meibauer, U.S. Pat. No. 4,338,957; Boggs, U.S. Pat. No. 5,016,660; and Gross, et al., U.S. Pat. No. 5,033,150. Some devices have been described which move a strand of floss in an up and down or hatchet-like motion between teeth. See, e.g., Garrett, U.S. Pat. No. 4,014,354; Moore, U.S. Pat. No. 4,235,253; Grollimund, U.S. Pat. No. 4,458,702; and McSpadden, U.S. Pat. No. 4,605,025. Additional devices have been described which combine both a back and forth motion and an up and down motion. See, e.g., Florindez et al., U.S. Pat. No. 4,307,740; Urso, U.S. Pat. No. 4,586,521; and Ritter, U.S. Pat. No. 5,069,233. Still other devices have been described which incorporate an approximate teeter-totter or see-saw action whereby floss reciprocates over an imaginary fulcrum which lies along the long axis of the device. See, e.g., Waters, U.S. Pat. No. 3,421,524; and Odneal et al., U.S. Pat. No. 5,085,236.
One problem with some of these devices is that they utilize a mere back and forth or horizontal manipulation of dental floss between teeth. It is well accepted in the dental community that mere back and forth manipulation of dental floss between teeth is ineffective in cleaning teeth surfaces. Therefore, devices which merely provide a back and forth sawing motion are ineffective for flossing purposes.
Another problem with these devices is that they use direct mechanical links to transfer energy from an electric motor to a flossing assembly. Due to the direct mechanical links, the flossing assemblies are not "forgiving" (i.e. they meet resistance with force). If when using one of these devices the flossing element comes in contact with soft mouth tissues, the tissues may very well be cut or abraded. In addition, if floss is moved between teeth in a rapid and/or strong back and forth motion, it can injure and damage mouth tissues. Furthermore, it is also well recognized that sharp or rapid up and down hatchet motions are more effective for flossing purposes, but are also potentially damaging to periodontal tissues.
Some devices include features to specifically address the potential injury problem. See, e.g., Meibauer, U.S. Pat. No. 4,338,957; and Grollimund, U.S. Pat. No. 4,458,702. However, the problems persist due to the direct mechanical links between the motor and the flossing assembly.
Energy, such as vibrational energy in sonic frequency ranges (e.g. 2,000 to 20,000 cycles per minute (cpm)), may be indirectly linked between a motor and a tool assembly. A sonic energy dental cleaning device is disclosed in Aurello et al., U.S. Pat. No. 3,466,689. Although the device described does not use direct mechanical links, it merely uses "acoustic streaming" (i.e. liquid under the influence of oscillatory forces) to clean teeth. This patent describes that teeth are not directly physically scrubbed or rubbed, rather the cleaning is accomplished completely by indirect acoustic streaming. However, as noted above, it is well accepted that hydraulic irrigation alone is not adequate to remove the sticky plaque films which build up on teeth surfaces including interproximal surfaces. There remains a need for a device which physically contacts teeth to clean them, but which does not utilize direct mechanical links.